If $$\mathrm{O}_{2}$$ gas is bubbled through water at $$303 \mathrm{~K}$$, the number of millimoles of $$\mathrm{O}_{2}$$ gas that dissolve in 1 litre of water is __________. (Nearest Integer)

(Given : Henry's Law constant for $$\mathrm{O}_{2}$$ at $$303 \mathrm{~K}$$ is $$46.82 \,\mathrm{k}$$ bar and partial pressure of $$\mathrm{O}_{2}=0.920$$ bar)

(Assume solubility of $$\mathrm{O}_{2}$$ in water is too small, nearly negligible)

A gaseous mixture of two substances A and B, under a total pressure of $$0.8$$ atm is in equilibrium with an ideal liquid solution. The mole fraction of substance A is $$0.5$$ in the vapour phase and $$0.2$$ in the liquid phase. The vapour pressure of pure liquid $$\mathrm{A}$$ is __________ atm. (Nearest integer)

$$150 \mathrm{~g}$$ of acetic acid was contaminated with $$10.2 \mathrm{~g}$$ ascorbic acid $$\left(\mathrm{C}_{6} \mathrm{H}_{8} \mathrm{O}_{6}\right)$$ to lower down its freezing point by $$\left(x \times 10^{-1}\right)^{\circ} \mathrm{C}$$. The value of $$x$$ is ___________. (Nearest integer)

[Given $$\mathrm{K}_{f}=3.9 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}$$; molar mass of ascorbic acid $$=176 \mathrm{~g} \mathrm{~mol}^{-1}$$]

When a certain amount of solid A is dissolved in $$100 \mathrm{~g}$$ of water at $$25^{\circ} \mathrm{C}$$ to make a dilute solution, the vapour pressure of the solution is reduced to one-half of that of pure water. The vapour pressure of pure water is $$23.76 \,\mathrm{mmHg}$$. The number of moles of solute A added is _____________. (Nearest Integer)